* gas/arm/itblock.s: New file. Helper macro for making all-true IT

* gas/arm/itblock.s: New file. Helper macro for making all-true IT
    blocks.
    * gas/arm/neon-cond-bad-inc.s: New test. Make sure unconditional
    Neon instructions are rejected...
    * gas/arm/neon-cond-bad.s: In ARM mode, and...
    * gas/arm/neon-cond-bad_t2.s: Accepted in Thumb mode (with IT).
    * gas/arm/neon-cond-bad.l: Expected error output in ARM mode.
    * gas/arm/neon-cond-bad.d: Control ARM mode test.
    * gas/arm/neon-cond-bad_t2.d: Expected output in Thumb mode.
    * gas/arm/vfp-neon-syntax-inc.s: Test VFP Neon-style syntax.
    * gas/arm/vfp-neon-syntax.s: ...in ARM mode.
    * gas/arm/vfp-neon-syntax_t2.s: ...and Thumb mode.
    * gas/arm/vfp-neon-syntax.d: Expected output in ARM mode.
    * gas/arm/vfp-neon-syntax_t2.d: Expected output in Thumb mode.